1. Field of the Disclosure
The present disclosure is directed to polymers and to methods for increasing the UV-absorbance, water resistance, and/or photostability of a variety of compositions comprising the polymers. More particularly, the disclosure relates to polymers comprising 2-cyano-3,3-diphenyl-prop-2-enoic acid moieties, to compositions comprising said polymers, and to methods of using the same, for example, a method of protecting a material from ultra-violet radiation, a method of waterproofing, a method of forming a film, and a method of photostabilizing a photolabile compound.
2. Brief Description of Related Technology
Ultraviolet radiation (light) can cause various types of chronic and acute damage to human skin. Overexposure to ultraviolet light having a wavelength from about 280 nm or 290 nm to about 320 nm (UV-B) can produce sunburn, while chronic overexposure can lead to skin cancer and weakening of the immune system. UV-B radiation is capable of causing damage to DNA by chemically altering the DNA structure. Both UV-A radiation (about 320 nm to about 400 nm) and UV-B radiation can damage collagen fibers and vitamin A in the skin, leading to a reduction of skin elasticity and accelerated aging of the skin.
Ultraviolet radiation from the sun or artificial sources also can damage coatings containing photoactive substances, such as photoactive pigments and dyes, by altering chemical bonds in the structure of a component, such as a polymer, a pigment, or a dye. This photodegradation can lead to color fading, loss of gloss, and loss of physical and protective properties of a coating.
The inclusion of UV-absorbing and photostabilizing compounds in compositions such as sunscreens and coatings can serve to reducing the damaging effects of UV radiation. U.S. Pat. Nos. 4,202,836 and 4,263,366, for example, provide UV light absorbing compounds to reduce weathering of polymeric coatings.